Thomas a



(No Model.)

T. A. EDISON.

DYNAMO ELBGTRIG MACHINE;

No. 263,140; Patented Aug.22, 1882.

UNITED STATES PATENT Orricit,

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters LPatent No. 263,140, dated August 22, 1882.

Application filed August 9, 1880. (No model.) Patented in England September 30, 1880, No. 3,964; in Germany February 3, 1881, No. 115,070; in Italy March '29, 1881; in Belgium l\[arch 31, 1881, No. 5 1,152; in Canada M'arch31,1881, No. 12,507; in India May 3, 1881, No. 336; in Victoria May 4, 1881, No. 3,005; in France May 27, 1881, No. 141,800; in Spain June 37, 1881; in Queensland June 30, 1881; in New South Vales July 4, 1881; in Austria July E21, 1881; in New Zcaland September 15, 1881, No. 551, d i

Portugal November '22, 1881.

To all whom it may concern Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in Magneto or Dynamo Electric Machines, (Case No. 224;) and I do hereby declare that thefollowing is a full and exact description of the same, reference being bad to the accompanying drawings, and to the letters of reference marked thereon.

The invention relates to that part of the machine known as the commutator-brush hold- As is well known, the commutator-brush generally used consists of a bundle of Wires or layers of sheet metal fastened in a frame or brush-holder in such position as to bear upon and make contact with the commutator.

As hitherto constructed the brush-holders have usually been rigidly attached to the frame of the machine with some device for adjusting them to different positions with relation to the commutator, and also so attached that if a commutator-brush became so damaged as to need repairs or replacement a stoppage of the machine was necessitated.

It is important that the pressure of the I brushes upon the periphery of the commutator should be constant and capable of adjustment to the desired degree, as when the pressure is too great the parts are too rapidly abraded and worn away, and when too slight an arc may form between the opposed surfaces or portions thereof, causing them to be burned or oxidized.

It is also important that provision should be made permitting the removal for repair or replacement of a brush without stoppage of the machine or interference with its capacity or the current transmitted.

The accomplishment of these results is the object of this invention; and to that end it consists in the features more particularly hereinafter set forth and claimed.

In the drawings, Figure 1 is a view of a commutator and series of commutatonbrushes embodying the invention; and Fig. 2 is a side view of one brush-holder, and Fig. 3 a longitudinal section of part of one brush-holder.

A is the commutator of a dynamo or magneto electric machine, placed, as usual, at the end of the rotating armature B, and supported at its outer end in bearings O, a (0 being the strips thereof connected to the coils of the armature, but insulated from each other.

At a suitable distance from the commutator square bars D D are supported in (but insulated from) supports DD, one of which only is shown.

The brush-holders are made in two pieces, E F, the part E being formed with a U-shaped recess orjaw at its upper end, in which takes and in which is pivoted the part F. A pin or pivot, '5, passes through the two parts and holds them together. In the lower portion of the part F a chamber is formed, in which is placed the spring h, whose inner end is attached to i, the outer end being fast to the wall of the'chamber. Upon the end of i, outside of the chamber, is a ratchet-wheel, 7a, a part, in, being arranged upon E to take into the teeth of k and hold it in a fixed position. In the upper or free end of F is a chamber or recess, f, for receiving and holding a brush, which is secured therein by a set-screw, 6. Upon the inner side of E is cut a groove the size of the bar D, in the under side of which is out a slot, as shown in Figs.2 and 3. A series of commutator-brush holders thus constructed are placed side by side uponthe bars D D by simply slipping each onto the bar from the front, each being secured thereon by the setscrew 61 taking into the groove on D. The use ofa series, as shown, involves several advantages. Each series of brushes is in metallic contact at the same time with the same strip or strips of the commutator; hence sparks between the commutator and brushes are greatly lessened, if not entirely obviated, and a large current can be conveniently taken from the machine with very little, if any, resistance thereto in the commutator. From these results I have applied the name large-current multiple brushes to this arrangement of brushes.

If repairs upon or replacement of one or more brushes be necessary, the set-screws d of the defective brushes are loosened and the holder of such defective brushes removed from the combination, with the commutator, of two series of brushes, (one upon each side,) each brush of a series being mounted independently upon a supporting shaft or bar common to all of its series, and provided with means within itself for adjustment of pressure independently of all the others of the series, substantially as set forth.

2. The combination, with a commutator, of a series of brushes and holders, each mounted independently upon a bar or shaft and arranged so that each brush takes obliquely upon the commutator, substantially as set forth.

3. A brush-holder formed of two parts, the one for fixed seating upon a proper support, the other connected thereto by an adjustable spring union, substantially as set forth.

4. In a dynamo or magneto electric machine, the combination of a bar for supporting the brushes, grooved upon one of its faces, and the brush-holder provided with a screw adapted to take in said groove, substantially as set forth.

5. A brush-holder having its end receiving the brush formed at an angle to its body, so that the brush may take obliquely upon the commutator, substantially as set forth.

This specification signed and witnessed this 30th day of July, 1880.

THOS. Ajnoison.

Witnesses:

WM. UARMAN, S. L. GRIFFIN. 

